In order to guarantee the precision of an electronic watch or clock comprising a quartz oscillator, a frequency divider and an electronic or electro-mechanical counter of seconds, minutes and hours, it is important to perfectly adjust the output frequency of the frequency divider. The method most generally utilized consists in adjusting the frequency of the oscillator by utilizing a capacitive trimmer connected in the quartz oscillation loop. This method has the main deficiencies of non-linear correction of the frequency as a function of angular displacement of the trimmer, poor stability thereof and a relatively small range of correction. Its utilization is, in contrast, very simple, the frequency correction being memorized by the angular position of the trimmer and not being affected by a change of the batteries.
Other procedures utilize a combination of memories which acts on the division rate of the divider, this rate being dependent on the program which has been preliminarily recorded in the memories. This programming is generally difficult to effect and especially it can vanish at the time of change of the batteries. It is necessary therefore, to provide a buffer accumulator which has low reliability and is relatively high in cost.